U.S. Pat. No. 4,822,213 issued Apr. 18, 1989 for a "Narrow Accessway Sewage Collection Tank Assembly, Remote Operated Quick Connect/Disconnect Coupling and System Using the Same"--Richard C. Grace, Jack L. Cooley and Eric F. Cabahug, inventors and assigned to Environment/One Corporation of Schenectady, N.Y., describes a narrow accessway sewage collection tank assembly and system using a remote operated, two-part, quick connect/disconnect slide coupling. The slide coupling is used to support a sewage pump within an enlarged collection tank for installation below normal ground levels of residential, commercial and industrial buildings. The narrow accessway passage is of sufficient cross-sectional dimension to allow free passage up and down for installation and/or removal of a liquid pump unit, but is insufficient in cross-section to accommodate passage of human beings.
A two-part, quick connect/disconnect slide coupling is provided for physically supporting the liquid sewage pump unit within a collection tank properly positioned relative to the bottom to assure proper scouring and prevent build-up of solids. The coupling allows ready installation or removal of the liquid sewage pump unit from the surface by a service man using a remotely operated tool to couple/ decouple the pump unit via the quick connect/disconnect, slide coupling and installing or withdrawing the liquid sewage pump unit downwardly/upwardly through the narrow accessway passage enclosure to the surface for ease of installation or removal for service, maintenance or replacement.
The quick connect/disconnect slide coupling described in U.S. Pat. No. 4,822,213 is suitable for many installations; however, its design is such that the integral stop valve structure which is part of the quick connect/disconnect slide coupling cannot be operated independently from the slide coupling used to mount the sewage pump. As a consequence, in this known coupling, it is necessary to remove or replace the movable portion of the slide coupling on which the sewage pump is secured in order to displace or move into its top valve position the slide stop valve portion of the coupling. In many circumstances, it is desirable or necessary that the slide stop valve be operable independently from the liquid sewage pump mounting structure, and to satisfy this need the present invention was devised.